Beam compass



E. LAXO I "BEAM COMPASS Jan. 25,1943.

Filed 001, 27, 1941 2 Sheets-Sheet l -26,1943, E. LAXO' v 2,309,514

BEAM COMPASS Filed oc. 27,' 1941 v 2 Sheets-Sheet 2 Ed Lqxo Patented Jan. 26, 1943 UNITED STATES PATENT OFFICE BEAM COMPASS Ed Laxo, Riverside, Ill.

Application October 27, 1941, Serial No. 416,725

Claims.

This invention relates to stability in refined adjustment of engineering tools.

This invention has utility when incorporated in manufacture from strip stock or ribbon, bar, and rod type of refinement in characteristics for locating and maintaining accuracy of dimension.

Referring to the drawings:

Fig. 1 is a plan view of a case in which the tool is assembled;

Fig. 2 is a view, with parts broken away, of the open case showing the grouping of the elements for the tool;

Fig. 3 is a view of the marker carrying pointer, from the end or side thereof from the right of Fig. 8, and having the supplemental minor adjustment;

Fig. 4 is a view from the opposite side or end of the marker, on the line IVIV, Fig. 8;

Fig. 5 is a view of the center pivot-or holding pointer at end or side elevation, showing the beam in section from the line V-V, Fig. 8;

Fig. 6 is a view of the opposite side or end of the pivot pointer on the line VI-VI, Fig. 8;

Fig. 7 is a view of an end elevation of the coupling for beam extension on the line VII- VII, Fig. 9;

Fig. 8 is an assembly, with parts broken away,

of the beam compass showing the pivot carrier or holder and the marker carrier; Fig. 9 is a view of the extension beam compass with the coupling assembly having the pivot carrier at the left on the line IX-IX,,Fig. 5, and the marker carrier on the line IX-IX, Fig. 3, with parts of the beam broken away;

Fig. 10 is a fragmentary view of the beam coupling on the line XX, Fig. '7; and I Fig. 11 is a section on the line XI-XI, Fig. 9, of the marker carrier.

Strip or ribbon stock may comprise channels I, 2, 3, fiat bars or beams 4, 5, spacer arms 6,

1 (Fig. 2), spacers 8, 9 (Fig. 9), ll] (Fig. 10),

for the cheeks of the channels, rod stock as-' sembly pins or rivets H (Fig. 9), arm carrying pins I2, clamp screw stems l3, adjusting screw stems i4, and, also from rod stock, nut l5, screw heads l6 (Figs. 3, 5, 9), and special screw head I! with swivel ball terminus l8 (Fig. 6). In the assembly set-up there thus remains merely rod stock of helical spring [9 (Fig. 9).

In, the carrying out of the invention herein,

there being clearance from the spacer to inturned-ears 22 providing a ledge or point at one end, opposing ledge 23 on the root 20 at the opposite end of way 24 through this carrier, wherein the spacer 8 is anchored by rivets H opposite the ledge points 22, 23, thereby to support threaded screw I4 having its head I! fixed or pressed thereon. This intermediate locking screw l4 thereby provides in this carrier a three point anchorage with the bar 4 of this beam compass, which three points are in the maximum dimension on narrow edges of this fiat beam. This means a maximum dimension distance of the three points from each other in substantial holding of this beam between the pair of cheeks 2|, which snugly rest thereag'ainst. At slight clearance as to this way 24 between the cheeks 2| is rivet or pivot l2. The arm 6 on the pivot !2 has its side 25 ride against the inner side of the root 20 and holds this arm against any shifting relatively to this carrier. This arm 6 as extending below the root 28 has therein adjusting screw l3 with the head l5 between fork portion 26 providing free ends 21. As the screw l3, I6, is adjusted, these way-providing portions 21 may clamp pointer tool 28 in adjusted position away from the beam 4, whether'such be for pivot point 29 or more tapering point 30 as in active position for the pivot. In this operation of the beam for this carrier to serve as the center or pivot, the spheric portion l8, as swiveled on the terminus of the screw [4 having the head I! fixed therewith, permits this holding of the instrument during the are or swinging operation independently of tendency to disturb the setting for this clamping screw l 4.

In the event the tool be used in a dimension wherein the one bar, either. the bar 4 or the bar 5 is sufiicient in extent, then a marker or complementary pointer carrier may be placed thereon. This complementary channel device I likewise has root 3| opposing cheeks 32, spacer 9, rivets H to anchor such spacer between the cheeks, ledges 22 and 23, and pivot rivet l2. Accordingly, the general assembly very much approaches a duplication of that for the pointer. the distinction being that the pin I2 is located away from the root 3| instead of adjacent thereto as with the pivot pointer. Furthermore, the arm 1 is pivoted on this pin or anchor l2. This arm 1 has forked free end 33 with the clamping screw l3 therebetween for adjusting the holding way 21 to carry marker tool 34, say a lead marker, crayon, or even inking device, or caliper pointer.

In the functioning of this tool, adjustment of the respective carriers for the pointers along the beam or beams may be by a definite anchorage or locking, that of this marking carrier being by the marking screw l4, l6, at the intermediate point between the ledges 22, 23. For extreme fineness of adjustment, the location between the pointer 29 and the marker or pointer 34 may on occasion be one as to which there is desired a minute further adjustment. To such end, between the forks 33, pin 35 may anchor threaded stem 36 for extending through opening 31 in the root 3|, there to receive the adjusting nut, 15. Between this arm 1 and this root 3| on this threaded rod 36 is compression helical spring 19. Accordingly, by this screw there is refinement of micrometer adjustment in the location of the point 34 and its spacing as to the point 29. With this spring IQ of a degree of stifiness there is no tendency to wobble nor is there such swing or accuracy disturbance feature between the respective channel carriers as mounting these pointers with the bar.

For a wider range of adjustment and retention of accuracy, a plurality of the bars may be adopted instead of extreme extension for one bar, thereby avoiding the cumbersome features of a long instrument when there may be desire to use for a short range as the shorter bar 5 readily adapts thereto. For the extension beyond that of the longer bar 4, there may be adopted hereunder a coupling, herein shown as channel mem her 3 having root 4!! (Fig. with spacer 10 between cheeks 4|. In addition to anchoring the rivets II at the spacer it] there is stop pin 42 determining the insert distance in way 43 for the respective bars 4, 5. There is here likewise a positive anchoring against side shift or wobble due to the clamping screws l4, l6, acting upon a narrow edge of the bar stock a major distance from the opposing edge as against the root 40.

This tool set-up may be one readily portable, wherein there is provided case having lower section 44, lid 45, hinges 46 therebetween, and catches 41 to lock the'case in closed position. This case base portion 44 has seat portions 48, 49, therein for the respective bars, seat portion 50 for the coupling, seat portion 5| for the marker carrier, and seat portion 52 for the pivot carrier.

Accordingly, in the operation hereunder, the engineer or operator may open the case 44, 45, select the bar 4 or 5 for the range of operation convenient. In the event such is for short radius, the bar 5 may have placed thereon the pointer carrier 2 with the nut l4, l1, locked to clamping position therewith, the pointer 29 having the desired placement and clamping through the action of its clamping screw l3, 6. Next in order is the slipping of the. marker screw on the remote portion of the bar 5 with its clamping screw l4, IS, in the approximate adjusted position along the bar for the radius sought between the pointer 9 and the marker 34, each as projecting narrow.-

wise away from the bar in said approximate plane of the wide range of the 'bar. For micrometer refinement in locating the pointer, the nut l5 may be adjusted. With this determination for the, arcor extent or curve or circle What is claimed and it is desired to secure by V Letters Patent is:

1. For a beam rider of a; drafting instrument beam, wherein the rider provides a leg comprising a channel forming an opening through which opening the beam extends, said channel depending from the opening with a pair of parallel cheeks providing ledges adjacent the beam to form a beam bearing at one side of the opening, a set screw through the intermediate portion of the rider at the opposite side of the opening from the ledges for engaging the beam to hold the beam against the ledges, of a pin between the cheeks and spaced from the beam on the side away from the set screw, a spacer arm on the pin and nesting between the cheeks and provided with a forked free end portion, and a fork adjusting screw, said fork having offset portions forming a seat for a pointer tool to be clamped by the screw.

2. For a beam rider of a drafting instrument beam, wherein the rider provides a leg comprising a channel forming a way through which way the beam extends, said channel being fixed with the rider in forming said way to guide the beam, of a spacer arm, and a pivot pin connection for mounting the arm in the channel to extend away from the beam guide Way, said arm having a forked clamp for mounting a pointer tool in adjusted position as to the channel.

3. For a beam rider of a drafting instrument beam, wherein the rider provides a leg comprising a channel having therethrough a guide way for the beam, said channel being fixed with the rider in forming said beam guide way, of a spacer arm, and a pivot pin connection for mounting the arm in the channel to extend away from the beam guide way, said arm having a forked clamp for mounting a pointer tool in adjusted position as to the channel, there being a connecting root portion at the channel and extending away from the beam and parallel to the arm.

4. For a pair of beam riders for a drafting instrument beam, adapted to be adjusted along the beam, wherein each rider comprises a leg including a parallel-cheek-providing channel fixed with the rider to extend about the beam and form a guide way for the beam, of a spacer arm, and a pin connection between the cheeks and spaced from the beam for mounting the arm to extend away from the beam guide way, said arm having a forked clamp for mounting apointer tool in adjusted position as to the channel, one of said riders being adapted for centering the instrument and having a connecting root portion at the channel between the cheeks and extending away from the beam and parallel to the arm for the arm to nest therein.

5. For a pair of beam riders for a drafting instrument beam, adapted to be adjusted along th beam, wherein each rider comprises a leg inc1uding a parallel-cheek-providing channel fixed with the rider to extend about thebeam and form a guide way for the beam, of a spacer arm, a pin connection between the cheeks and spaced from the beam for mounting the arm to extend away from the beam guideway, said arm having a forked clampfor mounting a pointer tool in adjusted position as to the channel, one of said riders being adapted for a marker and having a connecting root portion for the channel extending integral with and between the cheeks and extending away from the beam and parallel to the arm, and an adjusting screw for spacing the arm from said rootportion.

ED LAXO 

